Skysports.com understands that Rangers and Celtic have stepped up their interest in Sunderland defender Matthew Kilgallon after his move to Middlesbrough collapsed.
The former Sheffield United stopper is reportedly available for transfer after slipping down manager Steve Bruce's pecking order at the Stadium of Light.
Boro were unable to finalise a deal for Kilgallon, who has not been allocated a squad number, allowing the Old Firm to join the queue for his signature.
The 26-year-old is expected to leave Sunderland on loan before the window closes, but it remains to be seen whether he prefers the blue half of Glasgow or the green.
Kilgallon only joined Sunderland in January from the Blades and signed a three-and-a-half year contract, although he has made just six Premier League starts.